- The best treatment for ovarian and related female reproductive tract cancers is not yet known for patients whose disease has not responded to or has recurred after standard treatment. The cancer treatment drug pegaspargase (ONCASPAR (Trademark)), which works differently from standard chemotherapy, has been approved to treat leukemia and has been given to a small number of patient with ovarian and other types of cancer. Because pegaspargase may reduce the development of cancer cells and blood vessel cells that contribute to cancer growth and ability to spread, treatment with pegaspargase could shrink ovarian cancer tumors and help ovarian cancer patients live longer and with fewer symptoms from their disease.